Opinions? Please.

I usually wouldn't ask " could I be pregnant? " because my child is 2 & I know all the symptoms but this time, I just didn't know if what I'm feeling now is pregnancy symptoms because I think it's too soon. My fertile window was July 24th to the 29th. My fiance & I had sex on the 27th, 28th, 29th. Plus 2 more times before my fertile window had began. For the past 2 days, my breast are tender & I'm now awake at 6 am because I feel nauseous. Is it too soon to have pregnancy symptoms? My period isn't suppose to be here until August 10th.